NATURA BRESCIANA>> Ann. Mus. Civ. Se. Nat., Brescia, 30 (1994) 1996: 237-245

MARIO TOLEDO and PAOLO MAZZOLDI

TWO NEW FROM SOUTH-WESTERN CHINA

SUMMARY- Two new Dytiscidae, pederzanii n. sp. and Hydroporus nanpingensis n.sp., from Sichuan province, south-westem China, are described and compared with closely related species. Characters which allow separation of the new species from Rhantus yessoensis Sharp, Hydroporus uenoi Nakane and Hydroporus ijimai Nilsson & Nakane are provided.

RIASSUNTO - Due nuove specie di Ditiscide dal sud-ovest della Cina. Due nuove specie di Dytiscidae, Rhantus pederzanii n. sp. e Hydroporus nanpingensis n. sp., provenienti dalla provincia del Sichuan, Cina, vengono de­ scritte e confrontate con le specie vicine. Vengono identificati caratteri che consentono di separare le nuove specie da Rhantus yessoensis Sharp, Hydroporus uenoi Nakane e Hydroporus ijimai Nilsson & Nakane.

Recently, amid water material conected in southem China which we received from coneagues, we found specimens of a Rhantus and a Hydroporus which are new to science. W e therefore proceed to describe them. Abbreviations: CMSB, Civico Museo di Scienze Naturali, Brescia; FP, con. Fernan­ do Pederzani, Ravenna; PM, con. Paolo Mazzoldi, Brescia; MT, con. Mario Toledo, Bre­ scia.

Rhantus pederzanii n. sp.

Type materia!

Holotype: l o labened China, Sichuan, Sichuan prov., Gonga Shan Mt., Moxi, 21- 24.VII.l992, leg. Schneider J., CMSB; paratypes l o, 2 S?, same label as holotype, MT; 2 o o labened China, Sichuan, Kangding distr., 21-24.VII.l992, Hailougou Glacier Park, R. Dunda leg., MT; l o, l S?, same label as holotype, PM; l o, 2 S?, Sichuan prov., China, Tagu, Vl.1992, PM; 2 o, 2 S?, same label as holotype, FP.

Description

A large Rhantus. Oval, moderately elongate, dorsum convex; reddish yenow with a dark centrai spot on the pronotum and elytra with black irrorations (fig. 1). Length 14.8-

-237 15.6 mm, width 7.7-8.3 mm, the maximum width being situated just behind the middle of elytral length. Head reddish yellow with two large and well defined black markings around the eyes blending together on vertex and frons, leaving only a small heart-shaped yellow space (and sometimes a narrow longitudinal line) between them; therefore the head looks black in the basal half and yellow on the clypeus. The sculpture is in very high relief, consi­ sting of deeply incised wrinkles which are longitudinal on the vertex, especially behind the eyes, and partly longitudinal, partly transversal on frons and clypeus, where they delimit ir­ regular, polygonal meshes; some of the meshes have one or two punctures in their interior. Antennae reddish yellow, ante1momeres 4-11 darkened at the apex. Pronotum transverse, almost 3 times wider than long, a bit nanower than the base of elytra, therefore forming a weak pronoto-elytral angle; sides moderately rounded with a narrow, weakly developed latera! bead; base regularly arcuate at the center, weakly sinuate at the sides; basai angles rounded. Sculpture even com·ser and more impressed than on head, consisting in the anterior part of deeply incised wrinkles forming irregular subpolygo­ nal meshes, which give a coriaceous aspect to the surface; some of the meshes bear 1-2 punctures in their interi or. A l in e of bigger p une tures along the anterior bm·der of pronotum is hm·dly visible. Colour reddish yellow with a few scattered small black dots, pmticularly along the anterior and posterior margin, and with a darker transversal marking on the disk; the Jatter is however highly variable, sometimes round and small, sometimes more transver­ sely elongated and even broken into two symmetrical spots, sometimes hardly pronounced, almost obliterated. Elytra elongate: sides almost straight in anterior half, rounded posteriorly. Sculpture well impressed consisting of subpolygonal cells, some of which have a puncture inside; in the posterior part of the elytra a weak secondary reticulation can be seen at high magnifica­ tion inside the meshes. Two series of discal punctures are visible in the basai half. Colour reddish yellow irrorated with black spots, fused together in ve1miculations. A yellow stripe runs along the whole suture almost to the apex. Underside completely black. Sculpture on metastemum and stemites consisting of long, nanow cells, shmter on metastemal wings and epistemum. Surface rougher on meta­ sternum than on sternites. Prosternal process nanow, acuminated at the apex. Legs: femurs déu·k brown-black, pro- and mesofemurs paler at the apex. Tibiae and tm·si reddish yellow. ò: protarsi, especially tarsomeres 1-2-3, enlarged, with tufts of adhesive sucker hairs; tarsomere 5 as long as tarsomeres 1-4 together. Foreclaws long: the inner one as long as tar­ someres 3-4-5 together, straight seen from above and laterally, only slightly curved at the apex and with a small denticle near the base. The outer one a bit shorter, sinuate (see fig. 3a and 3b). Mesotarsi, especiall y tarsomeres 1-2-3, enlarged, tarsomere 5 as long as tarsomeres l-4 together. Both claws shorter than tarsomere 5: the outer one longer, straight, slightly curved, the inner one shorter (about 3/4 of the outer) and more strongly curved. Aedeagus as in fig. 2a and 2b, sharply bent just above the base, then almost straight, regularly tape­ ring towards the apex which, dorsally seen, cm·ves slightly to the right; parameres as in fig. 2c. S?: pro- and mesotarsi not differentiated, sculpture as in male.

Derivatio nominis

The new species is dedicated to our friend Fernando Pederzani.

238- E ,...E

Fig. 2- Apex of aedeagus in dorsal sight (a), aedeagus in latera] sight (b) and left paramere (c) of Rhantus pecler­ zanii n. sp.

Geographic distrihution

So far known only from Sichuan province, south-westem China.

-239 a

.'' :

Fig. 2- Apex of aecleagus in clorsal sight (a), aecleagus in latera! sight (b) anclleft paramere (c) of Rhalllus pecler­ :anii n. sp.

Discussion

The new species appears to be dose to yessoensis Sharp, described from Japan and al­ so recorded from China, to which it is similar in size, sculpture and shape of male fore­ claws. Although it was not possible for us to see specimens of yessoensis, it appears evìdent fì"om the descrìptions of yessoensis in ZIMMERMANN & GSCHWENDTNER (1936) and ZAlTZEV (1953) that pederzanii can be differentiated from yessoensis by the following characters: slightly bigger size (14-15 mm in pederzanii n.sp., against 13-14 in yessoensis Sharp), whi­ ch makes pederzanii the biggest palaearctic Rhantus; blaclc markings on the head more ex­ tended; claws of male protrarsi very long with outer claw longer than three quarters of the inner claw; penis first sharply bent and then almost straight, not regularly curved as in yes­ soensis. Furthermore, the two species seem to have a different geographic distribution, as yes­ soensis is known from Japan (SHARP, 1891), Korea: Quelpart Island (LEE et al., 1992), cast­ centrai China: prov. of Fujian and Jiangxi (ZIMMERMANN, 1920; FENG, 1932-33 and 1933- 34) while pederzanii is known only from Sichuan, more to the west.

240- b

E ,...E

Fig. 3- Left protarsal claws of Rhantus pedcr:canii n. sp. in latera] sight (a) and dorsal sight (b).

Hydroporus nanpingensis n. sp.

Type materia!

Holotype: l ò labelled China, N Sichuan, 30 Km W of Nanping, 13-l5.VI.1992, Juzhaigou, 3100 m, Jaroslav Turna leg. (the holotype is slightly damaged, lacking the left posterior leg and the last 4 tarsomeres of the right posterior one), CMSB; paratypes: 2 ò, 2 <;', same locality as holotype (ali more or less damaged, unfortunately no complete speci­ men is available), PM.

-241 a

b

0.25 mm

Fig. 4- Right protarsi of Hydroporus uenoi Nakane (a) and Hydroporus nanpingensis n. sp. (b).

Description

A small, piceous Hydroporus; body shape ovai somewhat elongate, with a slight con­ striction at the leve! of pronotal hind angles. Length 3.4-3.7 mm, width 1.7-1.8 mm, with maximum width at about the middle of the elytrallength. Head dark piceous, lighter coloured (reddish) only on clypeus and vertex. Two slight depressions are visible between the eyes, and the whole surface is covered by an evident re­ ticulation formed by small, regular, polygonal meshes and by a rather thick and strong punctation. Ante1mae with the first four articles testaceous, the others darkened; articles 3- 1O about twice as long as broad. Pronotum dark piceous with narrow but distinct latera! bead, latera! sides weakly cur­ ved; pronotal surface covered by a regular reticulation of small polygonal meshes and by a strong and thick punctation, the punctures being much thicker along the anterior and poste­ rior border than on pronotal disc. Elytra dark piceous, covered by a reticulation of small, polygonal meshes and by a strong and thick punctation. Underside black. Legs rufous to dark brown, male pro- and mesotarsomeres weakly dilated, with pro­ tarsal claws slender, not differentiated (fig. 4a). Penis as in fig. Sa, female gonocoxa and gonocoxosternum as in figs. 6a and 6b.

Derivatio nominis

The new species takes its name from the city of Nanping, near which it was collected.

242- Geographic distribution and ecology

So far known only from the type locality in Sichuan province, China. In this locality, which is a high altitude lake, it was collected together with Nebrioporus sichuanensis Hen­ drich & Mazzoldi, recently described (HENDRICH & MAZZOLDI, 1995), with which it must evidently share ecologica! requirements.

Discussion

The species clearly belongs to the group tristis and is closely related to uenoi Nakane and ijimai Nilsson & Nakane, recently revised and respectively described by NILSSON & NAKANE (1993). Thanks to the kindness of prof. Nilsson, who checked the determination of some specimens of uenoi, from eastem Siberia (Primorskii Krai, Ussuriisk, Kaimanovka, 2- 9.VIII.l992, leg. Boukal, 4 exx.; Amurland, Komsomolsk na Amur, Gornij Vili.,

a b 0.25mm

Fig. 5- Aedeagus in dm·sal sight of Hydroporus nanpingensis n. sp. (a) and Hydroporus uenoi Nakane (b).

-243 0.25mm:.__ __ -{

Fig. 6- Right gonocoxa (a) and right gonocoxosternum (b) of Hydroporus nanpingensis n. sp.

2.VII.1993, leg. Gorodinsky, 5 exx ali in MT and PM), we were able to compare nanpin­ gensis with uenoi, from which the new species can be easily differentiated by: a) the protar­ sal claws not differentiated (in uenoi the anterior protarsal claw is weakly but distinctly dif­ ferentiated, more robust and somewhat shorter, see figs. 4a and 4b); b) the punctures on the surface of head, which are distinctly bigger in nanpingensis; c) the colour of body, and in particular of elytra, which is darker in nanpingensis; d) the shape of penis, which although very similar is distinctly slenderer in its distai part in nanpingensis (see figs. 5a and 5b). W e could not see ijimai Nilsson and Nakane, but from this species nanpingensis may be easily distinguished because of the undifferentiated protarsal claws, as these are even more stron­ gly differentiated in ijimai than in uenoi. Obviously, the three species also have a different geographic distribution, since ijimai is known only from Hokkaido, uenoi from Hokkaido, Honshu and eastem Siberia and nanpingensis only from Sichuan.

244- ACKNOWLEDGEMENTS

W e thank our friends Ing. Fernando Pederzani, Ravenna, for putting at our disposa1 his specimens of Rhantus pederzanii n.sp., and Prof. Anders Ni1sson, Umea University, Sweden, for checking the determination of Hydropo­ rus uenoi Nakane.

REFERENCES

HENDRICH L. and MAZZOLDI P., 1995 - Nebrioporus sichuanensis n. sp. - ein neuer Schwimmkiifer aus Nordsi­ chuan, China (Coleoptera: Dytiscidae). Entomol. Z. 105 (1-2): 1-9. FENG H. T., 1933- Classification ofChinese Dytiscidae. Peking Nat. Hist. Bull. 8: 81-146. LEE S. H., CHo Y. B. and LEE C. E., 1992 - The Water of Quelpart Island (Coleoptera). Nature and Life (Korea), 22 (1): 45-60. MoRI M. and KITAYAMA A., 1993- Dytiscoidea ofJapan. Kankyou-kagaku Co. Ltd.: 1-218. [injapanese]. NILSSON N. A. and NAKANE T., 1993 -A revision ofthe Hydroporus species (Coleoptera: Dytiscidae) ofJapan, the Kuril Islands, and Sakhalin. Ent. scand. 23 (1992): 419-428. ZArrzEv F.A., 1953- Nasekomye zhestkokrylye. Plavuntsovye i vertyachki. Fauna SSSR, 58: 1-376. ZIMMERMANN A., 1920- Haliplidae, Dytiscidae et Gyrinidae. Bemerkenswerte Neuerwerbungen des Zoo1ogischen Museums in Hamburg. Entomol. BI. 16: 224-234. ZIMMERMANN A. und GSCHWENDTNER L., 1936- Monographie der palaearktischen Dytiscidae. VII. . (Colymbetini: Rhantus, Nartus, Melanodytes, Colymbetes, Meladema). Bestimmungs-Tabellen der europaei­ schen Coleopteren. 118. Heft (Ko1eopterologische Rundschau 22): 1-42.

Authors' address:

MARIO TOLEDO, via Tosoni 20-25124 BRESCIA (ltaly) PAOLO MAZZOLDI, via G. Galilei 87- 25128 BRESCIA (Italy)

-245